1. Technical Field
An aspect of the present disclosure may generally relate to an electronic device, and more particularly, to a semiconductor memory device and an operating method thereof.
2. Related Art
Semiconductor devices, particularly, semiconductor memory devices are generally classified into volatile memory devices and nonvolatile memory devices.
A nonvolatile memory device performs a read/write operation at a relatively low speed. However, the nonvolatile memory device retains its' stored data even when a power supply is cut off. Accordingly, the nonvolatile memory device is used to store data to be retained regardless of a power supply. Examples of the nonvolatile memory devices are a read-only memory (ROM), a mask ROM (MROM), a programmable ROM (PROM), an erasable programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), a flash memory, a phase-change random access memory (PRAM), a magnetic RAM (MRAM), a resistive RAM (RRAM), a ferroelectric RAM (FRAM), and the like. Flash memories are classified into NOR type flash memories and NAND type flash memories.
One benefit to using a flash memory is being able to freely program and erase the flash memory because of its' RAM. Also, flash memory has the advantage of implementing its' ROM in which stored data is retained even when a power supply is cut off. Thus, the flash memories are widely used as a storage medium for portable electronic devices such as a digital camera, a personal digital assistant (PDA), and an MP3 player.